<?php
      header('Content-type:text/html;charset=utf-8');
      const DISCOUNT =0.8;
      $fruit1='香蕉';
      $fruit2='苹果';
      $fruit3='橘子';
      $fruit1_num=2;
      $fruit2_num=1;
      $fruit3_num=3;
      $fruit1_price=7.99;
      $fruit2_price=6.89;
      $fruit3_price=3.99;
      $fruit1_total=$fruit1_num*$fruit1_price;
      $fruit2_total=$fruit2_num*$fruit2_price;
      $fruit3_total=$fruit3_num*$fruit3_price;
      $total=($fruit1_total+$fruit2_total+$fruit3_total)*DISCOUNT;
      $str="<table>";
      $str .="<tr><td>商品名称</td><td>购买数量（斤）</td><td>商品价格（元/斤）</td></tr>";
      $str .="<tr> <td>$fruit1</td> <td>$fruit1_num</td> <td>$fruit1_price</td></tr>";
      $str .="<tr> <td>$fruit2</td> <td>$fruit2_num</td> <td>$fruit2_price</td></tr>";
      $str .="<tr> <td>$fruit3</td> <td>$fruit3_num</td> <td>$fruit3_price</td></tr>";
      $str .="<tr><td colspan='3'>商品折扣:<span>".DISCOUNT."</span> </td></tr>";
      $str .="<tr><td colspan='3'>打折后购买商品总价格:{$total}元 </td></tr>";
      $str .="</table>";
      echo $str;